Gun defense question?

So...i'm trying to get a concealed weapons permit--purely for self defense because I'm a smokin' hot woman (lol). I was wondering, for the state of utah, what constitutes "self defense"? Yes, I know I can shoot at someone trying to kill me or me and get away with it...but what about someone trying to steal my purse? or my car? What are the limits of "self-defense"?